With noninvasive and nondestructive properties, an ultrasonic diagnostic apparatus is generally used in the medical field to obtain information of the inside of a subject. Since it is possible to provide a high-resolution image of internal organs of the subject to a doctor with no surgical operations of directly incising and observing the subject, ultrasonic diagnostic systems are very importantly used in the medical field.
An ultrasonic diagnostic apparatus is a system which transmits an ultrasonic signal from a body surface of a subject toward a target portion inside the subject, extracts information from a reflected ultrasonic signal, and obtains an image of a section of soft tissue or a blood flow in a noninvasive manner.
Compared with other imaging diagnostic apparatuses such as an X-ray inspection apparatus, a computerized tomography (CT) scanner, a magnetic resonance image (MRI) scanner, and a nuclear medicine inspection apparatus, since having a small size, being cheap, being capable of displaying in real time, and having excellent safety without being exposed to X-rays, such ultrasonic diagnostic system described above is generally used to diagnose hearts, internal organs in an abdominal cavity, urinary systems, and genital organs.
Due to an alternating current (AC) power source to which power is constantly supplied, a power shortage does not occur in a typical ultrasonic diagnostic apparatus. However, recently, as portable ultrasonic diagnostic apparatuses using batteries with limited power as power sources have been used, technologies for providing a maximum amount of usage time by minimum power are needed.